This invention pertains generally to orthopedic measuring devices. More particularly, the present invention pertains to measuring devices which are able to simultaneously measure mutually perpendicular linear displacements and angular displacements about an axis substantially perpendicular to the plane of the linear displacements. The present invention is particularly, but not exclusively, useful for measuring linear and angular displacements of the tibia with respect to the patella for the purpose of testing cruciate ligaments in the knee.